How does distance affect the force of gravity?

The force of gravity between any two objects is a function of their masses and the separation distance between them. The more the masses, the higher the gravitational force. The more the distance between them, the lesser is the gravitational force.
More accurately, as per the universal law of gravitation, the force of gravity (F) acting upon the two masses (with mass m1 and m2) and with a separation distance "d" between them is given by the following equation:
F = (Gm_1m_2 )/ d^2
This shows that the force is directly proportional to the product of masses and inversely proportional to the square of the distance between them. This means that if the mass of an object doubles, the gravitational force will also double. On the other hand, if the separation distance between two objects doubles, the gravitational force drops to 25% or 1/4 of its original value.
I hope this helps.